The present invention relates to an inverter apparatus for driving a compressor motor, which is a component of a refrigerator, an air conditioner, or the like.
An inverter apparatus is used to drive a compressor motor mounted in a refrigerator, an air conditioner, or the like.
The inverter apparatus comprises a board, a rectifier circuit mounted on the board, one or a plurality of smoothing capacitors mounted on the board, and a switching circuit mounted on the board.
The rectifier circuit rectifies the voltage of an AC power source. The smoothing capacitor smoothes a DC voltage output from the rectifier circuit. The switching circuit converts the DC voltage smoothed by the smoothing capacitor to an AC voltage.
The board is contained in a case, and fixed thereto by screws. The case is contained in an electric component box.
Recently, the components constituting the rectifier circuit and the switching circuit described above have been compact, and the heights of the components on the board have been considerably reduced.
A cylindrical electrolytic capacitor is used as the smoothing capacitor. Since the electrolytic capacitor has a height greater than those of the other components, it projects higher than the other components, when it is mounted on the board. For this reason, the height of the electric component box is determined in accordance with the height of the electrolytic capacitor. Therefore, although the components of the rectifier circuit and the switching circuit become compact, it is difficult to downsize the apparatus as a whole, because of the existence of the electrolytic capacitor.
A structure wherein the electrolytic capacitor is laid sideways is disclosed in U.S. Pat. Nos. 5,675,223, 5,610,493, EP 0688092, U.S. Pat. Nos. 2,525,436, 4,745,521, and 4,617,611. However, the structure wherein the electrolytic capacitor is simply laid is not very effective in reducing the height dimension of the entire apparatus.
An object of the present invention is to provide an inverter apparatus with a low height, so that the apparatus as a whole can be downsized.
An inverter apparatus of the present invention comprises:
a rectifier circuit for rectifying an AC voltage;
at least one cylindrical capacitor for smoothing a voltage output from the rectifier circuit, the capacitor having at a first end a gas-draining portion which is opened when an internal gas pressure is increased;
a switching circuit for converting the voltage smoothed by the capacitor to an AC voltage; and
a board on which the rectifier circuit and the switching circuit are mounted, the board having a notch at a corner;
a case having a first region for containing the board and a second region for containing the capacitor laid sideways through the use of the notch of the board, and ensuring a space necessary for the gas-draining portion of the capacitor contained in the second region to open, at a position corresponding to the gas-draining portion;
a lead wire drawn from the other end of the capacitor and guided to the first region in a state where the capacitor is contained in the second region of the case, the lead wire being bent at substantially right angles in the first region and connected to the board; and
resin used in the first region of the case and on the board contained in the first region.